Human Factors Guidelines for Interactive 3D and Games-Based ...

oth hierarchical and cognitive task analysis tools and those interested in this topic are
recommended to visit the DTC’s website (www.hfidtc.com) for further information 18 .
The type of analysis employed, then, often depends on a range of factors, including the Human
Factors specialist involved, whether or not the task exists in reality or has yet to be designed, the
goal of the analysis, any constraints imposed by the analysis environment and, of greatest
importance, the support and input of the end users and subject matter experts (SMEs).
Gaining access to the end users and SMEs, particularly in operational or field training settings, is
always difficult, particularly throughout the defence community. When opportunities arise, they are
typically characterised by short-duration sessions of quite intense activity, leaving the Human
Factors specialist with little time to record relevant data for use in subsequent task analyses or other
human-centred design processes. This problem is particularly acute where the outcome of a
project is to take the form of a simulation or Virtual Environment.
When there is a need for rapid results from analyses, the more popular techniques involve
observational and interview techniques, often supplemented with video and audio records (as have
been exploited for many of the HFI DTC case studies mentioned throughout this document). Other
techniques employ quite sophisticated computer-based solutions, from mixed media data recording
(video, computer keystrokes, physiological parameters, voice, etc.) to simulations based on models
of human physical and psychological performance.
As stated at the outset, this document aims to help make the i3D and serious gaming community
more aware of fundamental human interface issues, such as content, fidelity and interactive
technologies. Before tackling these issues, however, it is important to understand what to look for
when presented with an opportunity to undertake an observational analysis in the field. In addition
to the project outlines presented in Sections 3.0.1 to 3.0.4, below, Figures 13, 14, 15 and 16
(presented on pages 25 and 26) summarise the key observational factors recorded during end user
observational sessions undertaken in support of each of them.
3.0.1 Minimally Invasive Surgical Trainer (MIST; Figures 8 and 13).
The MIST system evolved from a project sponsored by the Wolfson Foundation and UK Department
of Health, the aim of which was to assess the potential of emerging Virtual Reality technologies to
deliver cost effective technology-based training for future surgeons. MIST was an early example of
the successful outcome of an HF task analysis undertaken in support of an i3D part-task skills
trainer, in conjunction with surgical subject matter experts. It was possible to isolate eight key task
sequences common to a wide range of laparoscopic cholecystectomy (gall bladder removal) and
gynaecological interventions and then define how those sequences might be modified or
constrained by such factors as the type of instrument used, the need for object or tissue transfer
between instruments, the need for extra surgical assistance, and so on. The close “coupling” (see
Section 4.4) between the surgeon and the patient, via the laparoscopic instruments, drove an early
decision to implement replica instruments, suitably modified to provide digital position and rotational
inputs into the computer.
Uniquely, MIST fosters laparoscopic skills not by training on virtual human bodies, but on carefully
selected task “primitives” (e.g. spheres, blocks, cylinders and wireframe task volumes of low visual
detail, or low “physical fidelity” – see Figures 8, 20 and Section 3.1), each designed following a
psychological breakdown of the perceptual and motor behaviours of observed surgeons 19 . MIST
18
See also: Stanton, N., Salmon, P., Walker, G., Baber, C., & Jenkins, D. (2005), “Human Factors Methods: A
Practical Guide for Engineering and Design”, Ashgate (December 2005).
19
Stone, R.J., & McCloy, R. (2004), “Ergonomics in Medicine and Surgery”, British Medical Journal, 328
(7448), 08 May, 2004, 1115-1118.
20